Self-setting liquid fuse



E. 0. SCHWEITZER. SELF SETTING LIQUID FUSE. QB BL ISATION FEED JUNE 21,191 8. 1 35 1 0 Y :Patented Nov. 9, 1920. 4

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E. 0. SCHWEUZER, SELF SETTING LIQUID FUSE. APPLICATION FILED JUNEZ],1918,

1 ,858, 1 80. Patented Nov. 9, 1920.,

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Patented N (W. 9, 1920.

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EDMUND D. SCEWEITZER, 0F GHI'CAGS, ILLINOIS;

SELF-SETTING mew rnsn.

:i'seease,

Specification of Letters Patent. Patented NQV. 9, 1920.

Application filed June 21, 1918. 7 Serial No. 241,284.

To aZZ whom/it may concern:

Be it known that I, EDMUND O; SCH\VE1T ZER, a citizen the United States,residing at Chicago, in the county of Cook and State Oi Tllinois, ha sinvented a certain new and useful Improvement in Self-Setting LiquidFuses, of which. the following is a full, clear, concise, and exactdescription, reference being bad to the accompanying drawings, formingpart of this specification.

My invention comprises a novel form of electrical apparatus termed by mea self setting liquid fuse.

This invention has been made to meet the demand for a device forrelieving'abnormal conditions of voltage on an electrical conductor. inelectrical generation and dis tribution abnormal rises of'voltage,surges 01" current oscillation and disturbances caused by switching andthe like, as well as disturbances directly caused by atmosphericelectricity, are all designated by the term lightning. There was a timein the history of the electrical art when atmospheric elec-g tricity wasthe chief and practically the only cause of disturbance on electriccircuits. As soon as any considerable voltage was employed so thatarcing would occur upon switching or a breakdown of theinsulation,'disturba'nces from the sudden making and breaking of the arcarose. ,The higher voltage coupled with a considerable current flow alsobrought out a peculiar electrical inertia ell'ect which may be observedin some degree on all electric circuits. Many other factors such asswitching of lines or transformers, starting of large pieces oiapparatus and the like, also con- 1 tribute to produce upon anelectrical sys-- tem abnormal conditions of voltage which may be of moreor less danger to the system.

Numerous forms of apparatus for reliev-- mg such undesirable conditlonshave been proposed. They are all designated by the general term oflightning, arresters.

7 Perhaps theone piece of apparatus that has found most favor in thiscountry for high tension transmission is'the electrolytic or aluminumcell arrester. The theory of this arrester has to do with the provisionof a workable condition.

a conductor characteriaed by a relatively large current carryingcapacity, but having a back electro-motive force substantially as greatas the line voltage, so that all excess voltage will have a free path toearth, but the line 'voltage .will be held back so that lzhe dynamicelectricity will be held on the The theory of the electrolytic arresteris verynice, but as every engineer who has had to deal with the deviceknows, there are many practical difiiculties which cause it to be farfrom an ideal arrester in practice.

One di'fficulty is the'necessity for introducing a gap between thearrester and the line to prevent leakage of current and heatquitefrequently to maintain the arrester in In case of repeated or heavyoperation there is danger'ot'heating the electrolytic arrester andcausing a dissolutionoi the film on the plate. If this occurs,destruction of the arrester is practically certain.

Almost any arrester permits the excessive voltage to go from line toground, but the diiticulty is to ..prevent the dynamic current fromfollowing the path established by the potential discharge, and theflowot dynamic current must not be cut off too sharply otherwisedisturbances are set up owing to the electrostatic capacity of the line.

I have conceived that if some means could be interposed in the line ofthe electrolytic arrester to make certain that the dynamic current wouldbe positively but gradually interrupted upon the flow of apro-determined ainount otenergy through the electrolytic arrester, thegreatest operating danger of the electrolytic 'arrester would beeliminated.

My observations and experiments have led me to the conclusion that theultimate criteriniiied amount of work.

the heat developed to cause the breaking of the dynamic current fiow.

The present invention aims to provide such a device.

I have found however that the device of .my invention being capable ofeliminating the danger of faulty operation of the electrolyticarresteryis of such a capabilityas to serve in and of itself as acomplete protective device without the electrolytic arrester.

to take the dangerous potential in relatively small successivedischarges closely following one another, a device of relatively smallca pacity would be able to handle a condition of almost any size.

It is well known to those skilled in the art'that the size or quantum ofthe disturbance cannot in any way be foretold. If the arrester is madesensitive enough to take care of relatively small disturbances. it willgen erally be destroyed upon the first disturbance of greater amount. Ihave conceived that if the disturbance could" be broken up into a numberof disturbances of smaller amounts, a protective device of small ca'pacity and relatively great SGDSIlZ'I VQHGSS would be able to handle adisturbance of any size.

It is the object of my-present invention to provide a method of andmeans for ac.

complishing this result.

The particular means .which I shall describe is but' one of a greatnumber of terms in which the invention may be embodied.

The means which I describe and illustrate in detail may operate in anumber of different ways to accomplish the broad purpose. I shall setthem forth in detail below.

It is well known .that current flowing through a conductor will be mademanifest by its activity therein. For instance, in passing a given flowof current through a resistance, a pre-determined amount of energy inthe form of heat energy will be liberated. This heat energy may do apre-de- Also the flow of a given amount of current through anelectrolyte will release a certain amount of chemical energy which mayalso be put to work. This energy which is developed by the flow ofcurrent, I employ in mechanically breaking the circuit to stop the flowof further current. That is to say. Iprovide an organization of partssuch that after the predetermined amount of disturbing current haspassed throughthe device, the circuit will be broken automatically. Theorganization is further provided for automatically remaking the circuitto let another pre-de- I have conceived that if it were possible Laseaeotermined amount pass out, and repeats until the disturbance is quelled.

The energy developed or released may be in the form of heat or chemicalactivity. It

is not advisable to develop the energy as magnetic energy because of thechoking etfect whlch such manifestation exerts upon the quick release ordischarge of the disturbance and-the consequent counter-disturbancewhich may be created. I have observed that the development of heat orchemical energy.

does not appear in any way to slow down or pervert immediate relief.

There are two general COllLlitiOIlS''llicllgfi" may employ my device toadvantage. The first condition is where a certain quantity of current isto befdischarged and repeated operation of the device is necessary topermit of such discharge. Under these circumstances the device of myinvention assumes the aspect of a controlling device for breaking up thedisturbance into parts and separately discharging the parts. In view ofthis aspect of the inventiorn I often term the same an electro-thermalvalve.

Under the condition which would exist where the amount of currentQndisturbance to discharged is no greater than that which is dependentupon the constants of the.

line and which can be conducted or discharged by the device before thesame operates to break the circuit, a different theory of action becomesmore prominent. In this aspect of the invention the discharge iscompleted substantially instantly. The apparatus then functions to cutoil the power current gradually enough to prevent disturbances. Theautomatic reestabllshment-of the circuit then becomes important inpreparing the device for the next operation. Under these conditions thedevice assumes the char; acteristics which make it valuable as a selfsetting fuse.

In one form of my invention which I have successfully operated. Iprovide a U-shaped receptacle for liquid of a relatively low con-'ductivity such as ater with a small amount of conducting material insolution.

the U. namely the longer, is open to atmosphere. The shorter leg isclosed at its upper end to form an electrode chamber. An electrodeprojects into the top of the chamber normally in contact with thesurface of the liquid. and a second electrode projects into the chamberbelow the level of the liquid at a predet rmined distance below thefirst electrode. lifhe resistance of theliquid or the vapor and liquidbetween the two electrodes determines the 'ate' at which electricalenergy may pass from the line or other conductor to be protected, toground or other conductor.

The invention is not limited to lightning The legs I of the U are ofunequal length. One leg of protection only, as may be employed to governtherate of current flow between two for'any other purpose. Iconsid'errupt b but. do not intend to limit the invention to such use. It is tobe understood further "that while I employ preferably a single unit, Ido not intend to'be limited to a singleunit, but may employ a battery ofthe same either in series or in parallel, or both.

One or" the most desirable features of a; lightning arrester and onewhich has not heretofore been feasible the ability to be connecteddirectly to the line. By providing'a small gap between the liquid andthe upper electrode as by maintaining the level lower than the topelectrode, I am ablevtoconnect the present device directly to the line.r

'In the accompanying drawing which form a part ofthe presentspecificatiom I have illustrated a particular embodiment of myinv'entioniwhich will teach those skilled in the art how toconstruct-and operate the invention.

Figure 1 is a diagrammatic layout of my invention employed in connectionwith an electrolytic arrester;

Fig. 2 18 a similar diagram of an embodiment showing the completelightning ar-- roster;

Fig. 3 is an enlarged sectional view of the device of my inventionshowing the electrodes and the interior of the gaseous chamber; v

Fig. is a diagram showing two of the devices employed in series;

Fig; 5 is an embodiment of the invention showing a series of cellsforming a modified form of arrester; and

Fig. 6 is a series of performance curves on various voltages.

Fig. 7 is a plan bottom view of the upper electrode. v

In Fig. l l have shown the device of my invention as connected betweenthe horn gap 2 and the electrolytic arr-ester 3 for protecting thetransmission line 1.

The horn gap 2 may be. of any preferred type and shown, consistsof thehorn eleccharge the electrolytic ar'rester 3, as is well understood bythose skilled in the art..

The horn clectrodeo is connected by means of the conductor 10 to theline wire 1 and the electrode 4 is connected through a flexiceparticularly adapted foriintera a the flow of high tension current,

"for instance, as pipe caps.

electrodes 20: and 21, the upper electrode her 39 which in this case isformed by a t 0t balrelite or other suitable insulat on as shown at 15,is provided with the upper and lower caps 16 and 17 respectively, thesecaps being preferably metallic caps such The bakelite sleeve 15 iscemented at its ends into the caps 16 and 17 as indicated at 18, to forma closed chamber.

"The closed chamber 19 contains the two 20 comprisinga pyramidal blockof graphite which is secured upon the stem 12which in turn is connectedas previously indicated, to the horn gap electrode 4.

The stem 12 passes :out through a stufiing 35, box 22 formed in thei1ipple23. The nipple" 23 is connected through suitable reducers 24;

and,25, to a coupling or nipple 26 which is mounted on the cap 16. Thestufiing box 22 is provided with a gland 27 and a fol lower formaintaining a fluid tight joint between the stem, 12- and the interiorof the chamber. l9.- The coupling or nipple 26 forms asmall chamber 29in communication with the chamber 19 for the collection. of vapors or agaseous medium which isevolved upon operation of the device as will bedescribed later. The chamber 29 is pro-l vided with a discharge pipe 30which has a nozzle 31 controlled by a needle valve 32. The purpose ofthis pipe, valve and nozzle is to permit vapors or a gaseous medium tobe dissipated or discharged from the chanb her 29 at a predeterminedrate.

The lower electrode '21 comprises a disk pipe communicating by way ofthe T 36 with a horizontal pipe 37. The horizontal pipe connects with avertical pipe 38, which opens at its upper end intoa storage cham- 12(,

larger piece of pipe communicating with atmosphere by the valve 60. Thepurpose of the chamber 39 is to receive the fluid which is dischargedfrom .the chamber 19. A controlling valve'or a checlcvalve with aby-pass may be interposed in the pipe connecting the chamber'l9 with thechamber- 39 for controlling the discharge of fluid to and from thechamber 89.

While I describe the storage leg of the U as 0pl\n to atmosphere, it isnot essential, as

. a clos'edchamber could be used under proper conditions.

The operation of the device as illustrated in Figs. 1 and 3 will now beunderstood from the following.

In case of a disturbance arising on the line 1 of suflicient voltage tobreak down the gap between the horn electrodes at and 5, it is desirableto provide a convenient-path to ground, ofsuch a character as to relievethe disturbance quickly but to positively break the flow of current in asmooth cycle to prevent potential rises after a predetermined quantityhas passed therethrough or after a given time interval.

The chamber 19 is normally filled with water to a point slightly belowthe discharge nozzle 31. The liquid will normally stand at the samelevel in both legs of the U shaped container. The liquid which I haveheretofore employed is common city water taken from the tap in the cityof Chicago. Other liquid might well be used, as will be apparent fromthe requirements under which this particular liquid is employed.

Current flowing from the line wire 1 across the horn gap 2conductedthrough the stem 12 and the electrode 20 through the body ofliquid between the electrodes 20 and- 21, and from thence to ground.

The resistance of this path is relatively high but as it is free ofinductance and is of relatively large capacity, if the disturbance uponthe line 1 is not of a sustained character, the discharge to earth willbe quick and easy. Theflow of dynamic current which tends to follow theflow of potential must always be positively interrupted, otherwise acontinuous loss would occur, and in the circuit indicated in Fig. 1, theelectrolytic arrester 3 would become heated up, and become ineffectiveif no positive interruption of the dynamic current were secured. Thehorn gap 2 is normally sufiicient to accomplish this, but under certaincircumstancesthe horn gap is insuflicient protection.

With my device in series with the horn gap and the ground connectionwhether including the electrolytic arrester or not, the

passage of current through the liquid .40

'causes'the same to be vaporized so that a body of vapor is trapped inthe chamber I 29 and as the current flow heats up the liquid, causingmore rapid generation of vapor. the

liquid ,will be forced down below the electrode 20, breaking the circuitcompletely. between the electrode 20 and the liquid by the interpositionof the steam or other gaseous medium whlc h is generated.

The discharge nozzle 31 which communicates with the chamber 29 governsthe rate at which the pressure is dissipated so as to control 'the timeinterval during which sufficient pressure will be generated to break thecircuit. The valve 32 thus becomes the means for regulating the devicefor controlling the rate at which current may flow through the device.The creation of a pressure of vapor or gaseous medium in the chamber 29will force the liquid down through the pipes 35, 37- and 38, into thereceiving chamber 39 where the liquid is stored up. \Vhen the circuithas been broken,

' the liquid will tend to flow back by gravity to close the circuitbetween theelectrodes 20 and 21 as fast as the pressure escapes by wayof the nozzle 31. I

The capacity of .the device maybe varied by varying the amount ofimpurity in the .wvater 4:0, or by substituting other liquids ormixtures of liquids. Numerous other factors may be varied to changeeither the rate at which pressure. is built up to drive the liquid outfrom between the electrodes or the rate at which current may passthrough the device. The distance between the electrodes 20 and 21 may bevaried by moving the stem 12, and for this purpose the stem 12 has beenpl'OVltlctl with graduations as indicated at -11,.so that accurateknowledge may be had ofthe distance between said electrodes. I I a Incase of a discharge of greater quantity 7 than the immediate capacity ofthe device of my invention, several successive operationsv of the devicewould occur.

upon the first flow ofcurrent, pressure would be generated in thechambers1929,

for the first amount of discharge than will be permitted for thesuccessive charges,

thereby tending to give instant relief but tocontrol successivedischarges so-that the device always maintains positive control over therate discharge.

The vaporization of the liquid gives a nongconducting gaseous body inthe upper part of the chamber which may consist in part'of the gasesformed by the dissociation of the water. In any event, the gaseousmedium which is thus generated is of a non- .conduct ng' character atleastfar belowv the conductivity of the water itself. so that thetendency is to interpose a non-conducting That is,-

and the liquid 40, andthe device may be connected directly to the line.c

In this condition the space at the t'opof 'the"chaniber19' is-normallyfull of vapor and the device stands ready to permit of a dischar e ofover potential at any time. In case the vapor should tend to dissipate,a small leakage current would tend to establish itselt and would reformthe jacket of vapor. Thus the device would be constan'tly ready forinstant action and the lag of the heating effect would be"considerablycut down.

In Fig. 2 have illustrated my invention as forming the sole protectivemeans for the line 1 without the electrolytic arrester shown in Fig. 1.The operation of the device is the same as previously indicated. Theadjustments forvdifi'erent voltages and capacities are obvious from theabove dis by means of the conductors 43, 4e and 455,

between the horngap' 2 and ground. The

upper ends of the liquid containing chambers are connected together bymeans of the pipe at). A common control valve 42 for governing the rate,of permitting the cscape of the gaseous mediuimis connected to thepipes6, and this valve insures operation. or the devices in unison.

from the foregoing description of a ,-1orrn oi the invention.

The chambers 39 which are made of. 1 sleeves or tubes of insulatingmaterial such as fiber connected together by a pipe 62 and this pipecommunicates with atmos -.phere through the valve 61.

The detailed operation will be apparent single In Fig. 5 have indicatedthe manner r in which a series or cells "embodying my invention may 6t},o

' -discharge valve 44) for governing the rate at be compactly arran edin a single casin and controlled by a common which the circuit isbroken. A series of inverted cups or cones which made of insula-iiionmounted upon a In order to avoid current flow.

51 which is also preferably made of insulation or of insulated sections,this tube having openings 52 communicating with the upper end of eachconical cup or shell 50.

fluid will be generated and will collect at thetop part of each cell,thereby. forcing the liquid away from the particular electrodes 54: andtending to increase the resistance to the passage of current at eachcell and thereby controlling the amount 0t The expansion of .thesteam orother. gaseous medium will force the liquid away from contact with theelectrodes 54: and will positively break the current at each point.After this occurs the gaseous medium will be dissipated at the valve 49and the circuit remade. Thus the operation is identical with theoperation described in connection with Figs. 1 and 3.

I have found that when the resistance 01' the liquid 4L0 and the vaporabove it is kept relatively high, the device may be connected directlyto the line without the use of the gap 2. However, I interpose the horngap'2 when the liquid connects the electrodes 20 and 21 as this avoidsthe constant loss which would otherwise occur.v I have employed a thinlayer of oil upon the top ofthe body of water e0. This prevents undulyrapid evaporation and also acts as a non-conductor which is interposedbetween the upper electrode 20 and the surface of the water.

' Where the surface of the water tOis maintained below the upperelectrode 20 the vapor space between the electrode and the water seemsto become ionized and very sensitive to rises in voltage permitting aquick discharge. The resultant evolution or" fresh -vapor by the dynamiccurrent breaks down surges are induced. A curve drawn through the peaksof the current flow curves takes the form of a rectangular hyperbola.

I am aware that water columns or sprays have been employed particularlyin England for the discharge of potential from transmission lines andthe like. However. I am laying no claim to such construction or methodof operation. I consider that my invention is entitled to a broadconstruction, and do not intend to limit thesame..except as may be setout in the appended claims.

I claim:

1. The method of breaking the flow of current through. aliquid whichcomprises conducting the current through the liquid at a rate sufficientto vaporize a part of the liquid. ther. causing thevapor to accumulateand displace a portion of the liquid to break the continuity of thecurrent flow independently ofthe rate of generation of said vapor.

2. The method of interrupting the flow of current in a liquid conductorwhich com: prises vaporizing apart of the liquid con ductor by the heatof the current flow. then causing the vapor so generated to beaccumulated and to exert a pressure upon a free surface of the liquidconductor to move the same down and out of conductingrelation.

3. The method of periodically interrupt ing a flow of current throughaliquid conductor whichcomprises causing the How of current to vaporize aportion of the'liquid conductor. then accumulating the vapor and causingthe'vapor to move a portion of said liquid conductor down and out ofconducting relation. then dissipating the vaporto permit the conductorto return to conducting relation.

4. The method of interrupting the flow of current through a liquid whichcomprises causing the current through the liquid to generate anon-conducting gaseous medium. accumulating said gaseous medium 'underpressure above the surface of the liquid. then moving the liquid by saidgaseous pressure down and out of conducting rclationto break the currentflow.

In a current interrupting device. a pair of electrodes and a conductingliquid between them. said liquid being adapted to evolve a relativelynon-conducting gaseous medium upon the passage of current therethroughand means for trapping the'gaseous medium above the freesurtacc ot theliquid one. of said electrodes being arranged near the normal surface ofthe liquid and adapted to lose contact with the liquid when the gaseousmedium is formed and trapped.

G. In a cm'r'ent interrupting device. a chamber. an electrod adj a centthe. upper end of the chamber. an electrode adjacent the lower end ofthe chambeigand liquid between said electrodes said chamber forming aclosed trap tor trapping vapor a conducting above the free surface ofthe liquid, a relatively large outlet for liquid at the lower 8. 111acurrent interrupting device. a pair of electrodes. a coiulucting liquidbetween them, said liquid being adapted to evolve a substantiallynon-conducting "apor upon the passage 0t current through the same,

and means to trap said vapor above the normal surface of the liquid andto displace the liquid.

9. In' a current interrupting device. a pair of electrodes. a conductingliquid between them. said liquid being adapted to evolve a relativelynonsconducting vapor for displacing the liquid between the electrodes.and means governing the dissipation of said vapor.

10. In combination. a U-shaped passageway having a closed chamber at.the top of one leg and a chamber at the top of the other leg. anelectrode in the upper end of the closed chamber. a body of liquid oflow coiuluctivitv in said closed chambe' and in said U-shaped conduit.an electrode forthe lower end of said closed chamber. means toradjusting the upper electrode. and means for controlling the rate ofdischarging liquid from said closed chamber.

ll. In combination. a closed chamber having an upper and a lowerelectrode. a body of liquid of low conductivity between said electrodes,ail-atmospheric leg communicating with said closed chamber. said legbeing adapted to receive the liquid discharged from the closed chamberwhen a pressure is created therein. 7

12. In combination. a sleeve of insulation. a metallic cap at each endof the sleeve. a bushing in the cap at the upper end of the sleeve. arod passing through said bushing. a stutling boX for the rod, anelectrode on the 'inner end of said rod. an electrode mounted on thelower metallic cap. and an atmospheric connection for receiving fluiddischarged from the sleeve comn'iunicating with the interior of thesleeve through the lower cap.

13. In combination..a sleeve of insulation. a metallic cap at each endof the sleeve. a bushing in the cap at the upper end of the sleeve. arod passing through said bushing. a stuiiing box for the rod, anelectrode on "the inner end of said rod, an electrode lower cap, and avalve governing the escape of fluid from .the upper end of the sleeve.

1d. The method of interrupting a flow of current from anelectrodethrough a liquid conductor which comprises vaporizing a part ofthe liquid bythe How of current, trapping the vapor soevolved above thesurface of the liquid and moving the liquid out of conducting relationby the pressure of vapor thereupon.

15. The method of relieving an electrical disturbance whichcomprisesconducting a flow of current from an electrode through a liquidconductor, generating a vaportrom the liquid by said flow, and causingsaid vapor to press upon the free surface of the liquid to move thelevel of the liquid cohductor downward far enough below the electrode tobreak the flow of current.

16. In combination, a liquid container, a body of liquid therein, anelectrode normally extending below the free surface of the liquid,- andconnections for causing a flow of cprrent from the electrode through theliquid, said flow of current being adapted to generate a gaseous mediumwhich rises through the liquid, said container having a closed topforming a gas or vapor accumulator above the level of the liquid foraccumulating said gaseous medium independently of the rate of flow ofcurrent -until suflicient pressure is accumulated abovethe free surfaceof the liquid to separate theliquid and the electrode.

17. Inca device of the class described, a

pair of chambers communicating with each other at their lower ends, anelectrode in one jchamber a 'li iiid standin norinall hi h enough inboth chambers to contact with the electrode, said one chamber having aclosed top to trap vapors and 'avent for permitting the dispersion ofvapors from said one chamber.

18. In combination, a pair of chambers connected together at their lowerends, one of said chambers being of greater capacity than the other, anadjustable electrode in the smaller chamber, a body of liquid in saidchambers, said smaller chamber having a closed top for trapping vaporfreed by the passage of current from said electrode through said liquid,and means "for dissipating the vapor trapped in said smaller chamber.

19. In combination, an electrical line, a pair of chambers connectedtogether at their lower ends, one of said chambers being ot greater cap;city than the other, an adjust able elec iod-e in the smaller chamber. abody oi liquid in said smaller chamber, said smaller ciher having aclosed top for trapping vapor freed by the passage of current from saidelectrode through said liquid, and a normallyopen connection between theelectrode and the line. V

'20. The method ot'iuterrupting a .tlow of current which comprisespassing the current from an electrode through a liquid. generating. apredetermined quantity of vapor for each unit of current flow,accumulating and trapping the vapor above the free sur :f'aceot theliquid about the electrode and progressively forcing the liquid downbelow and out of contact with the electrode bysaid accumulated vapor,the pressure of said gaseous medium serving to separate said conductingliquid and said electrode from each other.

21. In combination, an electrode, a liquid Iiormally in contact with theelectrode, a liquid container having a ,vapor trap at its upper end andmeans controlling the rate at which th e vapor may escapefrom said trap,the pressure in the vapor trap controlling the separation of theelectrode and the liquid.

22. In combination, an electrode, a body of water normally in contactwith the electrode, a tank having a vapor trap at its upper end, saidtank containing said electrode,and a vent having a valve for controllingthe rate at which vapor inay escape from said trap, the pressure of theva or in said trap controlling the separation of the liquid and theelectrode.

23. In combination, a pair of tanks closed at their upper ends andcommunicating with each other at their lower ends, a liquid having afree surface in each tank, an electrode in one tank normally in contactwith the 241. In combination, a liquid container L having a closed topforming a vapor trap, a body ot-water in said container, an electrodeprojecting through the container into contact with the water, saidelectrode being insulated from the container, a liquid outlet in thebottom of the container and a layer of oil on the free surface of thebody of water.

25. In combination, a tank having a trap for vapor at its upper end andan outlet for liquid at its lower end, a body of conducting liquid insaid tank having a free surface, an electrode projecting through the topof the tank into contact with said body ct liquid, said liquid being aconductonand a layer of insulating liquid. overlying said rec surface ofthe body of liquid.

26. n a device of the class described, a closed chamber having in upperportion a trap for vapor and adapted to hold liquid in its lowerportion, saicl'chamber liquid down below said electrode and anhaving anoutlet communicating with the fotherelectrode at all times in contactwith lower portion, and electrodemeans in the theliquid. l0 chamber. forgenerating a vapor from the In witness whereof I hereunto subscribe 5liquid, said electrode means comprising an my name this 17th day of JuneA. D. 1908.

upper electrode positioned within the liquid I I i so that trapping ofthe vapor will drix'e the EDMUND O. SCHlVEITZER.

